Final answer:
The equation of a line with given slope and x-intercept is found using the formula y = mx + b. Calculate the y-intercept by setting y to 0 and solving for b using the x-intercept. The slope is represented by m and the y-intercept by b in the equation.
Step-by-step explanation:
To write the equation of a line given the slope and x-intercept, you can start with the slope-intercept form of a linear equation, which is y = mx + b. The symbol m represents the slope, and b represents the y-intercept, which is the point where the line crosses the y-axis.
If you are given just the x-intercept instead of the y-intercept, you need to calculate the y-intercept before writing the equation. The x-intercept is the x-coordinate of the point where the line crosses the x-axis (where y=0). By substituting the x-intercept into the equation and knowing that the y-coordinate at this point is 0, you can solve for b.
For example, if the slope (m) is 3 and the line crosses the x-axis at 4, you would substitute these values into the equation y = 0 when x = 4 (for the x-intercept) and solve for b. This would give you the equation of the line as y = 3x + b. From there, you use a calculator to perform any necessary arithmetic to find b, the y-intercept, which may require additional information or context from the problem.
Therefore answer is a) y = mx + b.